JP6312118B2 - Electric characteristic measuring apparatus, electric characteristic measuring method and program - Google Patents

Description

  The present invention relates to an electrical property measuring apparatus, an electrical property measuring method, and a program for measuring electrical properties of a measurement object in a non-contact manner.

  Measurement of electrical properties including the electrical conductivity and relative dielectric constant of a liquid is necessary to grasp the composition change of the liquid, and monitoring of the electrical conductivity change is necessary for process control in the process industry. Become.

  Conventionally, there are mainly two methods for measuring conductivity, an electrode method and an electromagnetic method. The electrode type is a method in which the electrode is directly brought into contact with the liquid to be measured and the conductivity of the liquid is measured. In the electrode type, when a strong acid or strongly alkaline liquid is used as a measurement target, the electrode may be eluted into the liquid, and the original properties of the sample may be changed. In addition, it is difficult to use the electrode type for the purpose of monitoring, for example, the time-dependent change in conductivity until the concrete is set while the electrode is inserted, with concrete being an object of measurement.

  On the other hand, the electromagnetic method is a measurement method in which electromagnetic coupling is formed between two ring-shaped transformers (toroidal coils) via the liquid to be measured, and the energized portion of the detector and the liquid to be measured are not in contact with each other. It is possible to measure the conductivity in the state. An example of a conventional conductivity detector that employs an electromagnetic measurement method is disclosed in Patent Document 1.

  According to the electromagnetic measurement method, the toroidal coil itself is not in contact with the liquid to be measured, but it is necessary to insert the toroidal coil covered with the cover into the liquid. Therefore, as in the case of the electrode type, the cover material covering the toroidal coil may be eluted in the liquid.

  Examples of detectors that measure the electrical conductivity of a liquid in a completely non-contact manner include those described in Patent Documents 2 and 3.

JP 2010-85216 A JP-A-60-190873 JP 2001-153844 A

  As described in Patent Documents 2 and 3 above, by disposing the conduit through which the liquid flows so as to pass through the centers of the two toroidal coils, the conductivity of the liquid can be set in a completely non-contact state. It becomes possible to measure. However, these detectors detect the electromotive force generated in the toroidal coil on the output side in real time, so that they tend to be affected by perturbed electric fields and changes in charge in the liquid, and the measured values tend to be unstable. .

  The present invention has been made in view of the above points, and an electrical property measuring apparatus that can stably and non-contactly measure electrical properties such as conductivity and relative dielectric constant of a measurement object including a liquid, It is an object to provide a method and a program for measuring electrical characteristics.

According to the first aspect of the present invention, the measurement object is electromagnetically coupled to the container that accommodates the measurement object and the current flowing through the annular current path so that the measurement object forms an annular current path. and placed first toroidal coil and a second toroidal coil, a voltage input means for sequentially inputting a plurality of different AC voltage frequency to said first toroidal coil, is input before Symbol first toroidal coil Acquisition means for acquiring a frequency characteristic of at least one of a voltage ratio and a phase difference between an input voltage and an output voltage output from the second toroidal coil; and the voltage ratio and the level acquired by the acquisition means There is provided an electrical characteristic measuring device including deriving means for deriving an electrical characteristic of the measurement object based on at least one frequency characteristic of the phase difference.

According to the second aspect of the present invention, the frequency characteristic of at least one of the voltage ratio and the phase difference between the input voltage and the output voltage when the electrical conductivity and the relative dielectric constant in the container are known is a reference. The derivation means further includes a storage unit that stores the frequency characteristics in association with the electrical conductivity and relative dielectric constant, and stores a plurality of reference frequency characteristics corresponding to each of the plurality of electrical conductivity and relative dielectric constant, Of the plurality of reference frequency characteristics stored in the storage unit, a reference frequency characteristic closest to at least one of the voltage ratio and the phase difference acquired by the acquisition unit is extracted, and the extracted reference frequency An electrical property measuring apparatus according to a first aspect is provided that derives at least one of conductivity and relative dielectric constant corresponding to the property as electrical properties of the measurement object.

  According to a third aspect of the present invention, the derivation means includes a conductivity and a relative dielectric constant corresponding to a reference frequency characteristic that most closely approximates the frequency characteristic of the voltage ratio acquired by the acquisition means, and the acquisition means. A conductivity and a relative permittivity of the object to be measured are derived based on both a conductivity and a relative dielectric constant corresponding to a reference frequency characteristic that most closely approximates the frequency characteristic of the phase difference obtained by An electrical property measuring apparatus according to a viewpoint is provided.

According to the fourth aspect of the present invention, the measurement object is electromagnetically coupled to the container that accommodates the measurement object and the current flowing through the annular current path so that the measurement object forms an annular current path. and placed first toroidal coil and a second toroidal coil, a voltage input means for sequentially inputting a plurality of different AC voltage frequency to said first toroidal coil, is input before Symbol first toroidal coil Acquisition means for acquiring a frequency characteristic of at least one of a voltage ratio and a phase difference between an input voltage and an output voltage output from the second toroidal coil; and the voltage ratio and the level acquired by the acquisition means An electrical property measuring device including deriving means for deriving a determination result relating to identification or property of the measurement object based on frequency characteristics of at least one of the phase differences It is subjected.

According to a fifth aspect of the present invention, the apparatus further includes a storage unit that stores a reference frequency characteristic used as a determination criterion when the deriving unit derives a determination result related to the measurement object.
The deriving unit determines the measurement object based on a comparison result between at least one frequency characteristic of the voltage ratio and the phase difference acquired by the acquiring unit and a reference frequency characteristic stored in the storage unit. An electrical property measuring apparatus according to a fourth aspect for deriving a result is provided.

According to a sixth aspect of the present invention, the container includes an inlet-side channel into which the measurement object flows and an outlet-side channel from which the measurement object flows out, and the inlet-side channel There is provided an electrical property measuring apparatus according to any one of the first to fifth aspects, wherein a wall separating the outlet side flow path includes a semipermeable membrane.

  According to a seventh aspect of the present invention, the container includes a conduit through which the measurement object circulates, and a conductor wiring that is electrically connected to the measurement object whose both ends circulate in the conduit. An electrical property measuring apparatus according to any one of the first to fifth aspects is provided.

  According to an eighth aspect of the present invention, there is provided the electrical characteristic measuring apparatus according to any one of the first to seventh aspects, wherein the frequency of the AC voltage includes a range from 100 kHz to 1 MHz.

According to a ninth aspect of the present invention, the step of accommodating the measurement object in a container so that the measurement object forms an annular current path, and electromagnetically coupled with the current flowing through the annular current path. placing a first toroidal coil and a second toroidal coil as the steps of sequentially inputting a plurality of different AC voltage frequency to said first toroidal coil, is input before Symbol first toroidal coil Obtaining a frequency characteristic of at least one of a voltage ratio and a phase difference between an input voltage to be output and an output voltage output from the second toroidal coil, and a frequency characteristic of at least one of the voltage ratio and the phase difference Deriving an electrical property of the measurement object based on the above, an electrical property measurement method is provided.

According to a tenth aspect of the present invention, the step of accommodating the measurement object in a container so that the measurement object forms an annular current path, and electromagnetically coupled with the current flowing through the annular current path. placing a first toroidal coil and a second toroidal coil as the steps of sequentially inputting a plurality of different AC voltage frequency to said first toroidal coil, is input before Symbol first toroidal coil Obtaining a frequency characteristic of at least one of a voltage ratio and a phase difference between the input voltage to be output and an output voltage output from the second toroidal coil, and at least one of the frequency characteristics of the voltage ratio and the phase difference. And a step of deriving a determination result related to the measurement object based on the method.

  According to an eleventh aspect of the present invention, there is provided a program for causing a computer to function as the derivation means in the electrical characteristic measuring device according to any one of the first to eighth aspects.

  According to the electrical characteristic measuring device, the electrical characteristic measuring method, and the program according to the present invention, it is possible to stably measure the electrical characteristics of the measurement object in a non-contact manner.

It is a functional block diagram which shows the structure of the electrical property measuring apparatus which concerns on embodiment of this invention. 2A is a perspective view of the container according to the embodiment of the present invention, FIG. 2B is a top view of the container, and FIG. 2C is along line 2c-2c in FIG. 2B. It is sectional drawing. It is the front view and side view of the ferrite core which comprise the toroidal coil which concerns on embodiment of this invention. It is a block diagram which shows the hardware constitutions of the electrical property derivation | leading-out part and control part which concern on embodiment of this invention. It is a figure which shows the structure of the measurement system of the electrical property measuring apparatus which concerns on embodiment of this invention. 6A is a diagram showing a configuration in the case where reference frequency characteristic data is acquired using the electrical characteristic measuring apparatus according to the embodiment of the present invention, and FIG. 6B corresponds to FIG. 6A. It is an equivalent circuit diagram. FIG. 7A is a diagram showing the resistance value of the resistance element used when acquiring the reference frequency characteristic according to the embodiment of the present invention, and FIG. 7B is a diagram showing the capacitance value of the capacitance element. . FIG. 8A to FIG. 8C are graphs showing the reference frequency characteristics of the voltage ratio according to the embodiment of the present invention. FIG. 9A to FIG. 9C are graphs showing the reference frequency characteristics of the voltage ratio according to the embodiment of the present invention. FIG. 10A to FIG. 10C are graphs showing the reference frequency characteristics of the voltage ratio according to the embodiment of the present invention. FIG. 11A to FIG. 11C are graphs showing the reference frequency characteristics of the phase difference according to the embodiment of the present invention. FIG. 12A to FIG. 12C are graphs showing the reference frequency characteristics of the phase difference according to the embodiment of the present invention. FIG. 13A to FIG. 13C are graphs showing the reference frequency characteristics of the phase difference according to the embodiment of the present invention. It is a flowchart which shows the flow of a process in the electrical property measurement process program which concerns on embodiment of this invention. It is a flowchart which shows the flow of the 1st derivation | leading-out process which concerns on embodiment of this invention. It is a flowchart which shows the flow of the 2nd derivation | leading-out process which concerns on embodiment of this invention. It is a figure which shows the theoretical value of the density | concentration of the NaCl aqueous solution used as a measuring object in the electrical property measuring apparatus which concerns on embodiment of this invention, and an electrical conductivity and a dielectric constant. FIG. 18A is a graph showing the frequency characteristic of the voltage ratio acquired for the NaCl aqueous solution, and FIG. 18B is a graph showing the frequency characteristic of the phase difference acquired for the NaCl aqueous solution. It is a figure which shows the material and compounding ratio of the concrete used as a measuring object in the electrical property measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the measuring point in the case of measuring the electrical property of concrete using the electrical property measuring apparatus which concerns on embodiment of this invention. FIG. 21 (a) and FIG. 21 (b) are graphs showing time transitions of ambient temperature, humidity, and concrete surface temperature. FIG. 22A and FIG. 22B are graphs showing the time transition of the voltage ratio acquired for concrete. FIG. 23 (a) and FIG.23 (b) are graphs which show the time transition of the phase difference acquired about concrete. FIG. 24A is a graph showing the frequency characteristics of the voltage ratio acquired for concrete. FIG. 24B is a graph showing the frequency characteristics of the phase difference acquired for the concrete. It is a figure which shows the component of the dairy product used as a measuring object in the electrical property measuring apparatus which concerns on embodiment of this invention. FIG. 24A is a graph showing the frequency characteristics of the voltage ratio acquired for the dairy product. FIG. 24B is a graph showing the frequency characteristics of the phase difference acquired for the dairy product. It is a figure which illustrates the determination reference | standard in the case of determining the umami of dairy products using a frequency characteristic. FIG. 28A is a graph showing the frequency characteristics of the voltage ratio acquired for blood. FIG. 28B is a graph showing the frequency characteristics of the phase difference acquired for blood. Fig.29 (a)-FIG.29 (c) are figures which show the structure of the container which concerns on embodiment of this invention. It is a functional block diagram which shows the structure of the electrical property measuring apparatus which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same reference numerals are given to the same or equivalent components and parts.

[First Embodiment]
(Device configuration)
FIG. 1 is a functional block diagram showing the configuration of the electrical characteristic measuring apparatus 100 according to the first embodiment of the present invention. The electrical property measuring apparatus 100 is an electromagnetic type that measures electrical properties including the electrical conductivity and relative permittivity of a measurement object including a liquid contained in a container 20 in a non-contact manner using two toroidal coils 10 and 11. It is a measuring device.

  The container 20 is for containing a liquid to be measured for electrical characteristics. 2A is a perspective view of the container 20, FIG. 2B is a top view of the container 20, and FIG. 2C is a cross-sectional view taken along line 2c-2c in FIG. 2B. The container 20 has a rectangular ring shape so that the liquid to be measured filled in the container 20 forms an annular current path. The container 20 can be configured using a resin material such as acrylic. In one aspect of the present embodiment, the length L1 and L2 of the outer peripheral wall of the container 20 are 80 mm, the length L3 and L4 of the inner peripheral wall are 52 mm, and the height T is 15 mm, respectively. The plate thickness is set to 1 mm. Moreover, the average length L of the pipe line formed by the container 20 corresponding to the length of the broken line g in FIG. 2B is 260 mm. Note that the average length L is the total length of a line passing through the center of the conduit constituted by the container 20. Moreover, as FIG.2 (c) shows, the width W inside the pipe line of the container 20 is 13 mm.

In the present embodiment, each of the pair of toroidal coils 10 and 11 is configured by winding a litz wire having a bundle of 120 polyurethane coated conductors having a diameter of 0.05 mm around an annular ferrite core 10 times. In the present embodiment, N30 (base material: MnZn, initial permeability μ _i : 4300 ± 25%, magnetic field strength H: 1200 A / m, resistivity σ: 0.5 Ωm) manufactured by SIEMENS was used as the ferrite core. FIG. 3 is a front view and a side view of the ferrite core 12 constituting the toroidal coils 10 and 11. The ferrite core 12 has an outer diameter D1 of 50 mm, an inner diameter D2 of 30 mm, and a width E of 20 mm. The toroidal coils 10 and 11 are arranged so that the pipe line of the container 20 passes through the through hole 12a of the annular ferrite core so that the current loop formed in the container and the toroidal coils 10 and 11 are electromagnetically coupled. Placed in.

  In order to facilitate the removal of the toroidal coils 10 and 11 from the container 20, the ferrite core 12 is cut in half so as to cross the ring in advance, and the cut portions are joined by tie bands. When the ferrite core 12 cut in half is joined with a tie band, care must be taken to prevent foreign matters such as dust from adhering to the cut surface. If no foreign matter such as dust adheres to the cut surface, the magnetic path of the ferrite core 12 is completely closed and the relative permeability of the ferrite core 12 is high, so that a high mutual inductance (magnetic coupling) can be obtained. it can. Therefore, the measurement value of the electrical characteristic acquired by the present apparatus is not affected by cutting the ferrite core 12.

  The signal oscillator 30 is connected to a terminal of the toroidal coil 10 on the input side. The signal oscillator 30 is an oscillator that generates a sinusoidal AC voltage, and supplies the AC voltage to the toroidal coil 10 on the input side while sequentially changing the frequency based on a control signal from the control unit 60.

  The terminals of the input-side toroidal coil 10 and the output-side toroidal coil 11 are connected to a voltage ratio measuring unit 32 and a phase difference measuring unit 34, respectively. Based on the control signal supplied from the control unit 60, the voltage ratio measurement unit 32 outputs the effective value V1 of the input voltage input to the input-side toroidal coil 10 and the output voltage output from the output-side toroidal coil 11. The effective value V2 is measured, and the ratio V2 / V1 between the input voltage and the output voltage is derived by calculation and output.

  Based on the control signal supplied from the control unit 60, the phase difference measuring unit 34 determines the waveform of the input voltage input to the input side toroidal coil 10 and the waveform of the output voltage output from the output side toroidal coil 11. The phase difference between the phase P1 of the input voltage and the phase P2 of the output voltage is derived. The phase difference measurement unit 34 outputs the phase difference as a negative value when the phase P1 is delayed with respect to the phase P2, and sets the phase difference as a positive value when the phase P1 is advanced with respect to the phase P2. Output. The voltage ratio measurement unit 32 and the phase difference measurement unit 34 may be configured by, for example, a multichannel digital oscilloscope capable of performing arithmetic processing between channels.

  The storage unit 40 is configured to include a computer-readable storage medium such as a hard disk, a semiconductor memory, or an optical disk. When the electrical property deriving unit 50 described later derives the electrical property of the liquid stored in the container 20. The reference frequency characteristic referred to by the electrical characteristic deriving unit 50 is stored. The reference frequency characteristic will be described later.

  The electrical characteristic deriving unit 50 acquires the voltage ratio and phase difference of the input / output voltages of the toroidal coils 10 and 11 from the voltage ratio measuring unit 32 and the phase difference measuring unit 34 for each frequency, and the voltage ratio and the phase difference are obtained. Based on the result of comparing the frequency characteristics with the reference frequency characteristics stored in the storage unit 40, the electrical characteristics (conductivity and relative dielectric constant) of the liquid contained in the container 20 are derived. More specifically, the electrical characteristic deriving unit 50 selects and selects the frequency characteristic closest to the frequency characteristic of the voltage ratio and the phase difference from the plurality of reference frequency characteristics stored in the storage unit 40. The conductivity and relative permittivity corresponding to the reference frequency characteristic are derived as the conductivity and relative permittivity of the liquid to be measured.

  The control unit 60 supplies control signals to the signal oscillator 30, the voltage ratio measurement unit 32, the phase difference measurement unit 34, and the electrical characteristic derivation unit 50 at a predetermined timing, thereby controlling the operation timing of these components.

  As shown in FIG. 4, the electrical characteristic deriving unit 50 and the control unit 60 include a CPU 200, a ROM 201 (Read Only Memory) that stores various programs executed by the CPU 200, data used for arithmetic processing in the CPU 200, and the like. A computer including a RAM (Random Access Memory) 202 for temporarily storing, and a hard disk (HDD) 203 for storing voltage ratio and phase difference frequency characteristics supplied from the voltage ratio measuring unit 32 and the phase difference measuring unit 34 It is comprised including.

(Measurement principle)
FIG. 5 is a diagram illustrating a configuration of a measurement system of the electrical characteristic measurement apparatus 100 according to the embodiment of the present invention. The electrical characteristic measuring apparatus 100 forms electromagnetic coupling between the input-side toroidal coil 10 and the output-side toroidal coil 11 via a current loop formed by the liquid to be measured. That is, as shown in FIG. 5, the toroidal coil 10 on the input side corresponds to the primary coil 10a, and the toroidal coil 11 on the output side corresponds to the quaternary coil 11a. The liquid to be measured contained in the container 20 that is inserted through the through holes of the toroidal coils 10 and 11 can be regarded as the secondary coil 21a and the tertiary coil 22a of one turn.

  When an AC voltage is applied to the toroidal coil 10 on the input side corresponding to the primary coil 10a by the signal oscillator 30, a magnetic field in the direction of canceling the current is generated inside the toroidal coil 10 according to Ampere's law. As a result, the liquid corresponding to the secondary coil 21a generates an induced current in a direction that prevents the magnetic field. This induced current also flows through the tertiary coil 22a. Thereby, a magnetic field is generated in the toroidal coil 11 on the output side corresponding to the quaternary coil 11a, and as a result, an electromotive force is generated in the toroidal coil 11. In addition, since the leakage magnetic flux of toroidal coils 10 and 11 itself is small, even if an air layer exists between the container 20 and the toroidal coils 10 and 11, a high degree of coupling is maintained.

  The voltage ratio measuring unit 32 measures the effective value V1 of the input voltage input to the toroidal coil 10 on the input side and the effective value V2 of the output voltage output from the toroidal coil 11 on the output side. The ratio V2 / V1 is derived by calculation and output. The signal oscillator 30 sequentially applies a plurality of AC voltages having different frequencies to the toroidal coil 10 on the input side under the control of the control unit 60. Thereby, the frequency characteristic of voltage ratio V2 / V1 is acquired.

  The phase difference measuring unit 34 acquires the waveform of the input voltage input to the toroidal coil 10 on the input side and the waveform of the output voltage output from the toroidal coil 11 on the output side, the phase P1 of the input voltage, and the output voltage A phase difference from the phase P2 is derived. The signal oscillator 30 sequentially applies a plurality of AC voltages having different frequencies to the toroidal coil 10 on the input side under the control of the control unit 60. Thereby, the frequency characteristic of the phase difference between the input voltage and the output voltage is acquired.

  Since the frequency characteristics of the input / output voltages of the toroidal coils 10 and 11 and the frequency characteristics of the phase difference are determined according to the conductivity and relative permittivity of the liquid to be measured, the frequency characteristics of the voltage ratio and relative permittivity are acquired. Thus, it is possible to derive the conductivity and relative permittivity of the liquid to be measured. In the electrical characteristic measuring apparatus 100 according to the present embodiment, the frequency characteristic of the voltage ratio and phase difference acquired by the electrical characteristic measuring unit 50 for the liquid to be measured is used as a reference for the voltage ratio and phase difference stored in the storage unit 40. The conductivity and relative permittivity of the liquid to be measured are derived based on the result of checking with the frequency characteristics.

(Acquisition of reference frequency characteristics)
Below, the acquisition method of the reference frequency characteristic memorize | stored in the memory | storage part 40 is demonstrated. FIG. 6A is a diagram showing a configuration when reference frequency characteristic data is acquired using the electrical characteristic measuring apparatus 100, and FIG. 6B is an equivalent circuit diagram corresponding to FIG. 6A.

In the present embodiment, as shown in FIG. 6A, both ends of an RC parallel circuit in which a resistance element R and a capacitance element C are connected in parallel are connected by a conductive wire Y, and the conductive wire Y is accommodated in a container 20. Was used as a measurement circuit for obtaining the reference frequency characteristics. Conductive wire Y is arranged to pass through the through holes of toroidal coils 10 and 11. Such measurement circuit by configuring the, electric conductivity in the container 20 sigma, specific state filled with liquid dielectric constant epsilon _r is simulated. In other words, a current path having a conductivity σ and a relative dielectric constant ε _r is formed in the container 20. Here, when the dielectric constant of vacuum is ε ₀ , the average length of the conduit of the container 20 is L, and the sectional area of the container 20 is S, the resistance value r of the resistance element R and the capacitance value c of the capacitance element C are respectively These can be represented by the following formulas (1) and (2).

r = L / σS (1)
c = ε ₀ ε _r S / L (2)
In one aspect of this embodiment, the average length L and the cross-sectional area S of the container 20 are L = 260 mm and S = 130 mm ² (when liquid is filled from the bottom of the container 20 to a height of 10 mm), respectively, Since the dielectric constant ε ₀ is 8.8541 × 10 ⁻¹² F / m, when these values are substituted into the above equations (1) and (2), the following equations (3) and (4) Is obtained.

r = 2000 / σ (3)
^{_{c = ε r × 4.42705 × 10}} -15 ··· (4)
That is, by substituting the resistance value r of the resistance element R into the equation (3), the electrical conductivity σ of the liquid assumed to be filled in the container 20 can be obtained. For example, when the resistance value r of the resistance element R is 10Ω, a state in which the container 20 is filled with a liquid having a conductivity σ of 200 S / m is simulated. Further, by substituting the capacitance value c of the capacitive element C into the equation (4), the relative dielectric constant ε _r of the liquid assumed to be filled in the container 20 can be obtained. For example, when the capacitance value c of the capacitive element C is 1.0 pF, a state in which the container 20 is filled with a liquid having a relative dielectric constant ε _r of 225.9 is simulated.

Using the RC parallel circuit as described above, the reference frequency characteristics of the voltage ratio and the phase difference were obtained by the following procedure. First, the measurement circuit shown in FIGS. 6A and 6B is configured, and an AC voltage is applied to the toroidal coil 10 on the input side using the signal oscillator 30. Next, the voltage ratio measuring unit 32 and the phase difference measuring unit 34 are configured by setting the voltage ratio and phase difference between the input voltage input to the input side toroidal coil 10 and the output voltage output from the output side toroidal coil 11. Measure using an oscilloscope. Next, the frequency of the alternating voltage output from the signal oscillator 30 is changed, and the voltage ratio and the phase difference are obtained in the same manner as described above. In the present embodiment, the frequency of the AC voltage is changed by 100 kHz in the range of 100 kHz to 1 MHz, and the voltage ratio and the phase difference are acquired for each frequency. Thereby, the frequency characteristic of the voltage ratio and the phase difference corresponding to the resistance value r (conductivity σ) and the capacitance value c (relative permittivity ε _r ) is acquired. Next, the resistance value r and the capacitance value c are changed, and the frequency characteristics of the voltage ratio and the phase difference are obtained in the same manner as described above. In this embodiment, a resistance element R having a resistance value r shown in FIG. 7A and a capacitance element C having a capacitance value c shown in FIG. 7B are used, and the voltage ratio and phase difference of all of these combinations are used. The frequency characteristics were acquired. In FIGS. 7A and 7B, the values of conductivity and relative dielectric constant corresponding to each resistance value and each capacitance value are also shown. These electrical conductivity and relative dielectric constant are values calculated based on the above equations (3) and (4). As described above, the frequency characteristics of the voltage ratio and the phase difference acquired for each combination of the resistive element and the capacitive element are associated with the resistance value r (conductivity σ) and the capacitance value c (relative permittivity ε _r ). This is stored in the storage unit 40 as a reference frequency characteristic.

  8 to 10 are graphs showing the reference frequency characteristics of the voltage ratio obtained according to the above procedure. FIG. 8A, FIG. 8B, and FIG. 8C are frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 0 pF, 0.3 pF, and 1.0 pF, respectively. . FIGS. 9A, 9B, and 9C show frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 10 pF, 100 pF, and 200 pF, respectively. 10A and 10B show frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 500 pF and 1000 pF, respectively. In the graphs shown in FIGS. 8 to 10, the vertical axis represents the voltage ratio of the input / output voltages of the toroidal coils 10 and 11, and is logarithmic. The horizontal axis represents the frequency of the AC voltage input to the toroidal coil 10. In each figure, there are portions where the measurement points are insufficient in the range of 100 kHz to 300 kHz. This is because there was not enough voltage to measure the phase difference. In each figure, it can be confirmed that the amount of change in the voltage ratio decreases as the resistance value increases. This is presumably because the load resistance in the transformer increases and current does not flow easily, and the output voltage of the toroidal coil 11 corresponding to the quaternary coil decreases.

  11 to 13 are graphs showing the reference frequency characteristics of the phase difference obtained according to the above procedure. FIG. 11A, FIG. 11B, and FIG. 11C are frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 0 pF, 0.3 pF, and 1.0 pF, respectively. . FIGS. 12A, 12B, and 12C show frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 10 pF, 100 pF, and 200 pF, respectively. 13A and 13B show frequency characteristics for each resistance value when the capacitance value c of the capacitive element C is 500 pF and 1000 pF, respectively. In the graphs shown in FIGS. 11 to 13, the vertical axis represents the phase difference between the input and output voltages of the toroidal coils 10 and 11, and the horizontal axis represents the frequency of the AC voltage input to the toroidal coil 10.

(Operation of electrical characteristic measuring device)
Below, operation | movement of the electrical property measuring apparatus 100 which concerns on embodiment of this invention is demonstrated. FIG. 14 is a flowchart showing the flow of processing in the electrical characteristic measurement processing program executed by the CPU 200 operating as the control unit 60 and the electrical characteristic deriving unit 50. The program is stored in the ROM 201 and executed when a predetermined input operation is performed on an input unit (not shown) provided in the electrical characteristic measuring apparatus 100. It is assumed that the container 20 is filled with a predetermined amount of liquid to be measured. In the present embodiment, the predetermined amount is an amount at which the liquid level in the container 20 becomes 10 mm.

  In step S <b> 10, the control unit 60 supplies a control signal for outputting an AC voltage to the signal oscillator 30. The signal oscillator 30 that has received the control signal outputs an alternating voltage of a predetermined frequency and supplies it to the toroidal coil 10 on the input side. An output voltage is output between the terminals of the output side toroidal coil 11 by electromagnetic induction.

  In step S <b> 11, the control unit 60 supplies the voltage ratio measurement unit 32 and the phase difference measurement unit 34 with a control signal for acquiring the voltage ratio and phase difference between the input / output voltages of the toroidal coils 10 and 11. Thereby, the voltage ratio measuring unit 32 measures the voltage ratio of the input / output voltages of the toroidal coils 10 and 11 and supplies the measured value to the electrical characteristic deriving unit 50. The electrical characteristic acquisition unit 50 stores the measured value of the voltage ratio in the hard disk 203. On the other hand, the phase difference measuring unit 34 measures the phase difference between the input and output voltages of the toroidal coils 10 and 11 and supplies the measured value to the electrical characteristic deriving unit 50. The electrical characteristic acquisition unit 50 stores the measured value of the phase difference in the hard disk 203.

  In step S12, the control unit 60 determines whether or not the measured values of the voltage ratio and the phase difference have been acquired for all predetermined frequencies. If the control unit 60 determines that the measured values of the voltage ratio and the phase difference are not acquired for all frequencies, the control unit 60 shifts the process to step S13 and sets the measured values of the voltage ratio and the phase difference for all frequencies. If it is determined that it has been acquired, the process proceeds to step S14.

  In step S13, the control unit 60 supplies the control signal for changing the frequency of the AC voltage to the signal oscillator 30, and then returns the process to step S10. Thereby, the signal oscillator 30 supplies the input side toroidal coil 10 with an AC voltage having a frequency different from the frequency of the previously supplied AC voltage. By repeating the processing from step S10 to step S13, an alternating voltage that changes by 100 kHz in a frequency range of, for example, 100 kHz to 1 MHz is applied to the toroidal coil 10 on the input side, and the voltage ratio acquired for each frequency and The measured value of the phase difference is stored in the hard disk 203. Thereby, the frequency characteristic of the input / output voltage of the toroidal coils 10 and 11 and the frequency characteristic of the phase difference are acquired.

  In step S <b> 14, the electrical property deriving unit 50 executes a first derivation process for deriving the conductivity and relative permittivity of the liquid based on the frequency characteristics of the voltage ratio acquired for the liquid to be measured.

  That is, in the first derivation process, the electrical characteristic deriving unit 50 stores the frequency characteristic of the voltage ratio acquired for the liquid to be measured by executing the processes of steps S10 to S13 and the storage unit 40. By comparing with the reference frequency characteristic of the voltage ratio, the conductivity and relative dielectric constant corresponding to the reference frequency characteristic closest to the frequency characteristic of the voltage ratio acquired for the liquid to be measured are derived.

  Here, FIG. 15 is a flowchart showing a flow of the first derivation process executed by the electrical characteristic deriving unit 50 in step S14.

  In step S20, the electrical characteristic deriving unit 50 extracts the reference frequency characteristic of the voltage ratio corresponding to the identification number i from the storage unit 40.

In step S21, the electrical characteristic deriving unit 50 calculates the absolute value of the difference value between the voltage ratio acquired for the liquid to be measured and the voltage ratio in the reference frequency characteristic extracted in step S20 for each frequency. The electrical characteristic deriving unit 50 calculates a sum value S _i of absolute values of the difference values calculated for each frequency, and stores this in the RAM 202. The total value S _i is used as an index value indicating the degree of approximation between the frequency characteristic of the voltage ratio acquired for the liquid to be measured and the reference frequency characteristic extracted in step S20. That is, it can be determined that the two frequency characteristics are approximated as the total value S _i is smaller.

In step S22, the electrical characteristic deriving unit 50 determines whether or not the value of the identification number i matches the predetermined value n. The predetermined value n is a value equal to the number of reference frequency characteristics of the voltage ratio stored in the storage unit 40. If it is determined that the value of the identification number i does not match the predetermined value n, the electrical characteristic deriving unit 50 increments the value of i by 1 in step 23 and returns the process to step S20. By repeating the processing from step S20 to step S23, the total value S _i is acquired for all the reference frequency characteristics related to the voltage ratio stored in the storage unit 40. On the other hand, if the electrical characteristic deriving unit 50 determines that the identification number i matches the predetermined value n, the process proceeds to step S24.

In step S24, the electrical characteristic deriving unit 50 derives the conductivity and the relative dielectric constant corresponding to the reference frequency characteristic that minimizes the total value S _i calculated for each of the reference frequency characteristics related to the voltage ratio. That is, in this step, the conductivity and relative dielectric constant corresponding to the reference frequency characteristic closest to the frequency characteristic of the voltage ratio acquired for the liquid to be measured are derived.

  Referring to FIG. 14, in step S <b> 15, the electrical property deriving unit 50 performs a second derivation process for deriving the electrical conductivity and relative permittivity of the liquid based on the frequency characteristics of the phase difference acquired for the liquid to be measured. Run.

  That is, in the second derivation process, the electrical characteristic deriving unit 50 stores the frequency characteristics of the phase difference acquired for the liquid to be measured by executing the processes of steps S10 to S13, and the storage unit 40. By comparing with the reference frequency characteristic of the phase difference, the conductivity and relative dielectric constant corresponding to the reference frequency characteristic closest to the frequency characteristic of the phase difference acquired for the liquid to be measured are derived.

  Here, FIG. 16 is a flowchart showing the flow of the second derivation process executed by the electrical characteristic deriving unit 50 in step S15.

  In step S <b> 30, the electrical characteristic deriving unit 50 extracts the reference frequency characteristic of the phase difference corresponding to the identification number i from the storage unit 40.

In step S31, the electrical characteristic deriving unit 50 calculates, for each frequency, the absolute value of the phase difference acquired for the liquid to be measured and the difference value of the phase difference in the reference frequency characteristic extracted in step S30. The electrical characteristic deriving unit 50 calculates a sum value S _i of absolute values of the difference values calculated for each frequency, and stores this in the RAM 202. The total value S _i is used as an index value indicating the degree of approximation between the frequency characteristic of the phase difference acquired for the liquid to be measured and the reference frequency characteristic extracted in step S30. That is, it can be determined that the two frequency characteristics are approximated as the total value S _i is smaller.

  In step S32, the electrical characteristic deriving unit 50 determines whether or not the value of the identification number i matches the predetermined value n. The predetermined value n is a value equal to the number of phase difference reference frequency characteristics stored in the storage unit 40. If it is determined that the value of the identification number i does not match the predetermined value n, the electrical characteristic deriving unit 50 increments the value of i by 1 in step 33 and returns the process to step S30.

By repeatedly executing the processing from step S30 to step S33, the total value S _i is obtained for all the reference frequency characteristics related to the phase difference stored in the storage unit 40. On the other hand, when the electrical characteristic deriving unit 50 determines that the identification number i matches the predetermined value n, the process proceeds to step S34.

In step S34, the electrical characteristic deriving unit 50 derives the conductivity and dielectric constant corresponding to the reference frequency characteristic in which the sum S _i calculated for each of the reference frequency characteristics of the phase difference is minimized. That is, in this step, the conductivity and relative dielectric constant corresponding to the reference frequency characteristic closest to the frequency characteristic of the phase difference acquired for the liquid to be measured are derived.

  Referring to FIG. 14, in step S <b> 16, electrical characteristic deriving unit 50 derives the electrical conductivity and relative permittivity of the liquid based on the results of the first derivation process and the second derivation process. For example, when the values of the conductivity and relative permittivity derived in the first derivation process are equal to the values of the conductivity and relative permittivity derived in the second derivation process, the electrical characteristic deriving unit 50 The electrical conductivity and relative dielectric constant are output as the electrical conductivity and relative dielectric constant of the liquid to be measured. On the other hand, when the values of the conductivity and relative permittivity derived in the first derivation process are different from the values of the conductivity and relative permittivity derived in the second derivation process, the electrical characteristic deriving unit 50 The values of the conductivity and relative permittivity derived in the first derivation process and the average values (median values) of the conductivity and relative permittivity derived in the second derivation process are calculated for the liquid to be measured. You may output as electrical conductivity and a dielectric constant. Further, the values of the conductivity and relative permittivity derived in the first derivation process and the values of the conductivity and relative permittivity derived in the second derivation process are used as the conductivity and relative permittivity of the liquid to be measured. The upper limit value and lower limit value of the estimated value may be output.

(Verification of measurement accuracy)
Using the electrical property measuring apparatus 100 according to the embodiment of the present invention, the electrical conductivity and relative dielectric constant of a NaCl aqueous solution having a known theoretical value of electrical conductivity and relative dielectric constant at 25.0 ° C. are measured, and the obtained measurement The measurement accuracy in the electrical property measuring apparatus 100 was verified by comparing the value with the theoretical value.

  In this experiment, three types of NaCl aqueous solutions having different concentrations were prepared, and each was designated as A, B, and C. FIG. 17 shows the theoretical values of the concentration, conductivity, and relative dielectric constant of each NaCl aqueous solution. Each NaCl aqueous solution was prepared using ion-exchanged water manufactured by Daiwa Kaken Co., Ltd. and Naruto bittern salt from Naruto Shiogyo Co., Ltd. Further, the NaCl aqueous solution was adjusted to 25.0 ° C. by immersing the container 20 filled with the NaCl aqueous solution in warm water. By filling the NaCl aqueous solution from the bottom of the container 20 to a height of 10 mm and changing the frequency of the alternating voltage applied to the toroidal coil 10 by 100 kHz in the range of 100 kHz to 1 MHz, the voltage ratio of the input and output voltages of the toroidal coils 10 and 11 The frequency characteristics of phase difference were obtained. The results are shown in FIGS. 18 (a) and 18 (b).

  FIG. 18A is a graph showing the frequency characteristic of the voltage ratio, and FIG. 18B is a graph showing the frequency characteristic of the phase difference. This is probably because there were insufficient measurement points, but there was not enough voltage to obtain the phase difference.

The procedure for deriving the electrical characteristics of the NaCl aqueous solution A is as follows. First, a frequency ratio reference frequency characteristic (see FIGS. 8 to 10) that approximates the voltage ratio frequency characteristic acquired for the NaCl aqueous solution A is searched. It can be seen that the reference frequency characteristic of the voltage ratio corresponding to the resistance value of 5 kΩ to 10 kΩ and the capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the voltage ratio in the NaCl aqueous solution A. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIG. 7A and FIG. 7B, respectively, the conductivity of the NaCl aqueous solution A that can be estimated from the frequency characteristics of the voltage ratio is 2 ^{.0 × 10 -1 S / m~4.0 ×} 10 -1 S / m, the dielectric constant is derived to be 0~2.259 × 10 ^4.

Next, a phase difference reference frequency characteristic (see FIGS. 11 to 13) that approximates the phase difference frequency characteristic acquired for the NaCl aqueous solution A is searched. It can be seen that the reference frequency characteristic of the phase difference corresponding to the resistance value of 10 kΩ and the capacitance value of 1 pF to 100 pF approximates the frequency characteristic of the phase difference in the NaCl aqueous solution A. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIGS. 7A and 7B, respectively, the conductivity of the NaCl aqueous solution A that can be estimated from the frequency characteristics of the phase difference is 2. 0.0 × 10 ⁻¹ S / m, and the relative dielectric constant is derived from 6.777 × 10 ^{1 to} 2.259 × 10 ⁴ .

Here, the range in which the electrical conductivity and the relative dielectric constant derived based on the voltage ratio and the frequency characteristic of the phase difference as described above overlap is set as the estimated range of the electrical conductivity and the relative dielectric constant of the NaCl aqueous solution A. That is, the estimated range of the conductivity of the NaCl aqueous solution A finally derived is 2.0 × 10 ⁻¹ S / m, and the estimated range of the relative dielectric constant is 6.777 × 10 ^{1 to} 2.259 × 10 ^4. It becomes.

The procedure for deriving the electrical characteristics of the NaCl aqueous solution B is as follows. The frequency ratio reference frequency characteristics (see FIGS. 8 to 10) that are approximate to the voltage ratio frequency characteristics acquired for the NaCl aqueous solution B are searched. It can be seen that the reference frequency characteristic of the voltage ratio corresponding to a resistance value of 1 kΩ and a capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the voltage ratio in the NaCl aqueous solution B. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIG. 7A and FIG. 7B, respectively, the conductivity of the NaCl aqueous solution A that can be estimated from the frequency characteristics of the voltage ratio is 2 0 S / m, and the relative dielectric constant is derived from 0 to 2.259 × 10 ⁴ .

Next, a phase difference reference frequency characteristic (see FIGS. 11 to 13) that approximates the phase difference frequency characteristic acquired for the NaCl aqueous solution B is searched. It can be seen that the reference frequency characteristic of the phase difference corresponding to the resistance value of 1 kΩ to 2 kΩ and the capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the phase difference in the NaCl aqueous solution B. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIG. 7A and FIG. 7B, respectively, the conductivity of the NaCl aqueous solution B that can be estimated from the frequency characteristics of the phase difference is 1. It is derived that 0.0 S / m to 2.0 S / m and the relative dielectric constant is 0 to 2.259 × 10 ⁴ .

Here, the range in which the electrical conductivity and the relative dielectric constant derived based on the voltage ratio and the phase difference frequency characteristics as described above overlap is set as the estimated range of the electrical conductivity and relative dielectric constant of the NaCl aqueous solution B. That is, the estimated range of the conductivity of the NaCl aqueous solution B finally derived is 2.0 S / m, and the estimated range of the relative dielectric constant is 0 to 2.259 × 10 ⁴ .

The procedure for deriving the electrical characteristics of the NaCl aqueous solution C is as follows. A reference frequency characteristic (see FIGS. 8 to 10) of the voltage ratio that approximates the frequency characteristic of the voltage ratio acquired for the NaCl aqueous solution C is searched. It can be seen that the reference frequency characteristic of the voltage ratio corresponding to the resistance value of 500Ω to 1 kΩ and the capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the voltage ratio in the NaCl aqueous solution C. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIG. 7A and FIG. 7B, respectively, the conductivity of the NaCl aqueous solution C that can be estimated from the frequency characteristics of the voltage ratio is 2 It is derived that the relative dielectric constant is 0 to 2.259 × 10 ⁴ and 0.0 S / m to 4.0 S / m.

Next, a phase difference reference frequency characteristic (see FIGS. 11 to 13) that approximates the phase difference frequency characteristic acquired for the NaCl aqueous solution C is searched. It can be seen that the reference frequency characteristic of the phase difference corresponding to the resistance value of 500Ω to 1 kΩ and the capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the phase difference in the NaCl aqueous solution C. When the above resistance value and capacitance value are converted into conductivity and relative dielectric constant with reference to FIG. 7A and FIG. 7B, respectively, the conductivity of the NaCl aqueous solution C that can be estimated from the frequency characteristics of the phase difference is 2. It is derived that the relative dielectric constant is 0 to 2.259 × 10 ⁴ and 0.0 S / m to 4.0 S / m.

Here, the range in which the electrical conductivity and the relative dielectric constant derived based on each of the voltage ratio and the frequency characteristic of the phase difference as described above overlap is set as the estimated range of the electrical conductivity and the relative dielectric constant of the NaCl aqueous solution C. That is, the estimated range of the conductivity of the NaCl aqueous solution C finally derived is 2.0 S / m to 4.0 S / m, and the estimated range of the relative dielectric constant is 0 to 2.259 × 10 ⁴ .

  As a result, the electrical conductivity derived for each of the NaCl aqueous solutions A, B, and C was very close to the theoretical value shown in FIG. From this, it was proved that the electrical property measuring apparatus 100 according to the embodiment of the present invention has sufficiently high measurement accuracy.

(Measurement of electrical properties of concrete)
Using the electrical property measuring apparatus 100 according to the embodiment of the present invention, the electrical conductivity and relative permittivity of concrete whose electrical properties are unknown were measured over a period from fresh properties to setting. FIG. 19 shows the concrete materials and blending ratios to be measured.

  The container 20 was filled with concrete to a height of 10 mm from the bottom, and the avatar was pulled out by applying vibration to the side surface and the bottom of the container 20 for 15 seconds. Until 60 hours elapse from the measurement start time, the frequency of the AC voltage applied to the toroidal coil 10 is changed by 100 kHz in the range of 100 kHz to 1 MHz at each time point shown in FIG. The frequency characteristics of voltage ratio and phase difference of voltage were obtained. It is known that the electrical properties of concrete change in a few hours due to its fresh properties. For this reason, the measurement interval was shortened during this period.

  Simultaneously with the measurement of the electrical properties of the concrete, the ambient temperature (room temperature), humidity and concrete surface temperature at each measurement point were measured. Ambient temperature and humidity were measured using a life management temperature and humidity meter (EMPEX, TM-2416). The concrete surface temperature was measured using a radiation thermometer (CUSTOM, IR-303). The radiation thermometer receives the amount of infrared energy radiated from an object in the vertical direction, and measures the temperature of the object by detecting it with a sensing sensor. However, since the amount of infrared radiation radiated from an object varies depending on the material and the surface condition, it is necessary to make corrections according to the emissivity of each substance. Here, in order to perform accurate temperature measurement, concrete was corrected for measurement, and measures were taken to obtain an accurate emissivity by bringing a radiation thermometer closer so that infrared rays radiated to the concrete surface would not diffuse.

  The time transition of ambient temperature, humidity, and concrete surface temperature is shown in FIG. 21 (a) (time transition from the measurement disclosure time to 60 hours) and FIG. 21 (b) (time transition from the measurement start time to 360 minutes). .

  FIGS. 22 (a) and 23 (a) show the time transitions from the measurement start time of the voltage ratio and phase difference of the input / output voltages of the toroidal coils 10 and 11 to 60 hours, respectively, from the measurement start time to 120 minutes. The time transition is shown in FIG. 22 (b) and FIG. 23 (b), respectively. FIG. 24 shows frequency characteristics of voltage ratio and phase difference at 0 minutes, 20 minutes, 1 hour 40 minutes, and 60 hours from the measurement start time. 22 to 24, the measurement points at 100 kHz and 200 kHz are insufficient, and this is considered to be because there was not a sufficient voltage to obtain the phase difference.

  From FIG. 21 (a) and FIG.21 (b), it can confirm that the change has occurred in the surface temperature of concrete between 6 hours from the measurement start time. This is thought to be due to the heat of hydration generated by the chemical reaction of the cement from the time of kneading to the setting. Due to the chemical reaction, the surface temperature of the concrete increased to 23.9 ° C. after 2 hours and 10 minutes from the start of measurement, then gradually decreased, and after 6 hours, decreased to 21.5 ° C. After 8 hours to 10 hours, the concrete surface temperature approached the ambient temperature (room temperature) due to thermal equilibrium, and after 10 hours became substantially the same as the ambient temperature.

  As shown in FIG. 22 (b), there was a slight change in the voltage ratio 20 minutes and 100 minutes after the start of measurement. Moreover, as shown to Fig.22 (a), it was confirmed that the voltage ratio has fallen with time progress from 10 to 20 hours after the measurement start time. This is thought to be due to the fact that the current contained in the sample is less likely to flow due to the decrease in moisture contained in the sample as the concrete congeals. After 20 hours from the start of measurement, the voltage ratio variation was small and almost constant.

  As shown in FIG. 23B, a change in phase difference was observed 20 minutes after the start of measurement. Further, as shown in FIG. 23 (a), it was confirmed that the phase difference decreased with the passage of time from 10 hours to 20 hours. This is thought to be due to the fact that the current was less likely to flow due to the decrease in moisture with the setting of the concrete. After 20 hours from the start of measurement, the fluctuation of the phase difference was small and almost constant.

  As shown in FIG. 24, it was confirmed that the electrical characteristics of the concrete changed with the passage of time within the period from the fresh properties to the setting.

Using the measurement principle of the electrical measurement apparatus 100 according to the embodiment of the present invention, the electrical characteristics of the concrete after 0 minutes from the measurement start time were estimated as follows. A frequency ratio reference frequency characteristic (see FIGS. 8 to 10) that is approximate to the voltage ratio frequency characteristic after 0 minutes from the measurement start time is searched. It can be seen that the reference frequency characteristic corresponding to the resistance value of 10 kΩ to 100 kΩ and the capacitance value of 0.3 pF to 10 pF approximates the frequency characteristic of the voltage ratio after 0 minutes from the measurement start time. Next, a reference frequency characteristic (see FIGS. 11 to 13) of the phase difference approximate to the frequency characteristic of the phase difference after 0 minutes from the measurement start time is searched. It can be seen that the reference frequency characteristic of the phase difference corresponding to the resistance value of 10 kΩ to 100 kΩ and the capacitance value of 10 pF approximates the frequency characteristic of the phase difference after 0 minutes from the measurement start time. As the point where the range of the resistance value and the capacitance value derived from the frequency characteristic of the voltage ratio and the range of the resistance value and the capacitance value derived from the frequency characteristic of the phase difference overlap, the vicinity of 10 kΩ and the vicinity of 10 pF are derived. Thus, the electrical conductivity of the concrete after 0 minutes from the measurement start time is estimated to be about 2.0 × 10 ⁻¹ S / m, and the relative dielectric constant is 0 to 2.259 × 10 ³ .

Next, the electrical properties of the concrete 60 hours after the measurement start time were estimated as follows. A frequency ratio frequency characteristic approximate to the voltage ratio frequency characteristic 60 hours after the measurement start time is searched (see FIGS. 8 to 10). It can be seen that the reference frequency characteristic of the voltage ratio corresponding to the resistance value of 100 kΩ to 10 MΩ and the capacitance value of 0 pF to 1 pF approximates the frequency characteristic of the voltage ratio 60 hours after the start of measurement. Next, reference is made to the reference frequency characteristic (FIGS. 11 to 13) of the phase difference that approximates the frequency characteristic of the phase difference 60 hours after the measurement start time. It can be seen that the reference frequency characteristic of the phase difference corresponding to the resistance value of 100 kΩ to 10 MΩ and the capacitance value of 0 pF to 100 pF approximates the frequency characteristic of the phase difference 60 hours after the start of measurement. The ranges of the resistance value and the capacitance value derived from the frequency characteristic of the voltage ratio overlap with the range of the resistance value and the capacitance value derived from the frequency characteristic of the phase difference are in the vicinity of 100 kΩ to 10 MΩ and in the vicinity of 0 pF to 100 pF. Thus, the electrical conductivity of the concrete 60 hours after the start of measurement is about 2.0 × 10 ⁻⁴ S / m to 2.0 × 10 ⁻² S / m, and the relative dielectric constant is 0 to 2. 259 × 10 ² is estimated.

  Thus, the conductivity of concrete decreased with time, and after 60 hours, the result was 1/10 to 1/100 of the initial state. The relative permittivity is difficult to estimate accurately because of its width, but has decreased from 2259 to 226 between 0 minutes and 60 hours after the start of measurement (however, when the maximum value is used) ), It was confirmed that the relative permittivity tends to decrease with drying.

(Measurement results of electrical properties of dairy products)
Using the electrical property measuring apparatus 100 according to the embodiment of the present invention, electrical properties of three types of dairy products X, Y, and Z with known milk fat content were measured. The components of the dairy products X, Y, and Z to be measured are shown in FIG.

  The dairy products X, Y, and Z are filled up to a height of 10 mm from the bottom of the container 20 and the frequency of the AC voltage applied to the toroidal coil 10 is changed by 100 kHz in the range of 100 kHz to 1 MHz, and the inputs and outputs of the toroidal coils 10 and 11 are made. The frequency characteristics of voltage ratio and phase difference of voltage were obtained. FIG. 26A is a graph showing the frequency characteristics of the voltage ratio acquired for the dairy products X, Y, and Z, and FIG. 26B is a graph showing the frequency characteristics of the phase difference. FIG. 26 (a) also shows the reference frequency characteristic of the voltage ratio corresponding to the capacitance value 10pF shown in FIG. 9 (a). In FIG. 26 (a), the frequency characteristics for the dairy products X, Y, and Z are each displayed with a broken line, and the reference frequency characteristics are displayed with a solid line. Similarly, FIG. 26B also shows a reference frequency characteristic of a phase difference corresponding to the capacitance value 10 pF shown in FIG. In FIG. 26B, the frequency characteristics for the dairy products X, Y, and Z are displayed with broken lines, and the reference frequency characteristic is displayed with a solid line.

  The frequency characteristic of the voltage ratio of the dairy products Y and Z is close to the reference frequency characteristic of the voltage ratio corresponding to the capacitance value of 10 pF and the resistance value of 2 kΩ to 5 kΩ in the band of 400 kHz to 1 MHz, but the band of 100 kHz to 400 kHz. Then, it approximates a reference frequency characteristic of a voltage ratio corresponding to a capacitance value of 10 pF and a resistance value of 5 kΩ or more.

  The frequency characteristic of the phase difference of the dairy product X approximates the reference frequency characteristic of the phase difference corresponding to the capacitance value of 10 pF and the resistance value of 5 kΩ at 300 kHz, and the reference frequency of the phase difference corresponding to the capacitance value of 10 pF and the resistance value of 2 kΩ at 1 MHz. Approximate characteristics. Further, at 400 kHz, the phase differences between the dairy products Y and Z match, and at 160 kHz, the phase differences between the dairy products X and Z match. As shown in FIG. 26 (b), the frequency characteristics of the phase differences acquired for the dairy products X, Y, and Z are all different from the reference frequency characteristics.

  In general, it is known that an NaCl aqueous solution hardly changes in electric conductivity and relative dielectric constant even when the frequency changes. Therefore, the frequency characteristics approximate to the frequency characteristics of the voltage ratio and phase difference acquired for the NaCl aqueous solution are extracted from the reference frequency characteristics on the assumption that the conductivity and the relative dielectric constant are constant at each frequency. Was possible. However, dairy products X, Y, and Z have complex components, and the conductivity and relative permittivity change with the change in frequency, and as a result, frequency characteristics different from the reference frequency characteristics are obtained. Conceivable.

  This indicates that there is a possibility that this apparatus can be used for identifying liquid components. That is, by observing the frequency characteristics of the voltage ratio and the phase difference, there is a possibility that this apparatus can be used for comprehensive analysis of various components, determination of umami, and the like as well as milk fat content. From the measurement result of the current dairy product, for example, if the curve indicating the frequency characteristic of the phase difference is in both the area A and the area B surrounded by the broken line shown in FIG. 27, it can be determined that the milk is delicious. There is sex.

(Measurement result of electrical characteristics of blood)
The electrical property measurement apparatus 100 according to the embodiment of the present invention was used to measure blood electrical properties. Sterile sheep preserved blood (manufactured aseptically collected from healthy animals and mixed with Alsever's solution (ALSEVER'S SOLUTION) as a blood to be measured) used. In addition, in order to simulate hypermagnesemia, which is one of the conditions requiring artificial dialysis, measurement was also performed on a sample obtained by adding magnesium to the blood.

  The above-mentioned blood sample is filled up to a height of 10 mm from the bottom of the container 20 and the frequency of the alternating voltage applied to the toroidal coil 10 is changed by 100 kHz in the range of 100 kHz to 1 MHz, and the voltage of the input / output voltage of the toroidal coils 10 and 11 is changed. The frequency characteristics of ratio and phase difference were obtained. FIG. 28A is a graph showing the frequency characteristic of the voltage ratio, and FIG. 28B is a graph showing the frequency characteristic of the phase difference.

  It was confirmed that the frequency characteristics of the voltage ratio and the phase difference change depending on the concentration of magnesium added. Moreover, in the phase difference in 100 kHz, although the difference by the difference in magnesium concentration does not appear, the difference by the difference in magnesium concentration became clear by measuring the phase difference in the several frequency more than 100 kHz. This is because it is difficult to appropriately analyze the component of the liquid to be measured only by measuring the voltage ratio and the phase difference at one frequency, but the voltage ratio at a plurality of frequencies as in this embodiment. If the phase difference is measured, the component analysis of the measurement target can be performed appropriately. Further, it is possible to obtain more information by measuring both the frequency characteristic of the voltage ratio and the frequency characteristic of the phase difference.

  The above measurement results are obtained by determining whether dialysis is completed by measuring the electrical characteristics of blood or dialysate using the electrical characteristic measuring apparatus 100 according to the embodiment of the present invention, for example, in artificial dialysis. Shows the possibility that can be done. As described above, when the electrical property measuring apparatus 100 according to the embodiment of the present invention is used in the medical field, passages such as blood and dialysate as exemplified in FIGS. 29 (a) to 29 (c). By using the container 20 that also serves as a non-contact, the electrical characteristics of these liquids can be measured. Since non-contact measurement is possible, infection and blood clots can be prevented. In the example shown in FIGS. 29 (a) and 29 (b), the container 20 has a dialysis membrane (semi-permeable membrane) 29 with a wall separating the inlet-side flow channel through which the liquid flows in and the outlet-side flow channel through which the liquid flows out. It consists of As a result, the inlet side and the outlet side of the container 20 are electrically connected to form a current loop, and the electrical characteristics can be measured by the electrical characteristics measuring apparatus 100 according to the present embodiment. In place of the dialysis membrane (semipermeable membrane) 22, it is possible to use an extremely thin insulating membrane. In the example shown in FIG. 29C, both ends of the conductor wiring 24 that is electrically connected to the liquid flowing in the pipe line of the container 20 that is not formed into an annular shape are connected to the pipe line. Also by such an aspect, a current loop can be formed, and the electrical characteristics can be measured by the electrical characteristic measuring apparatus 100 according to the present embodiment.

  As is clear from the above description, according to the electrical property measuring apparatus 100 according to the embodiment of the present invention, the electrical property of the liquid can be measured without contact with the liquid to be measured. Even if the liquid is a strongly acidic or strongly alkaline liquid, the measurement can be performed without contaminating the liquid to be measured. It is also possible to measure substances such as concrete that cause condensation over time. In this case, the electrical characteristics are continuously monitored over a relatively long period from the liquid state to the setting. It is also possible to use this apparatus for such purposes. In addition, this apparatus is also preferably used when measuring electrical characteristics of foods, pharmaceuticals, biological samples (blood, body fluid, dialysate, etc.) that require hygiene and require quick measurement. It is possible.

  Further, according to the electrical property measuring apparatus 100 according to the embodiment of the present invention, the electrical property of the liquid to be measured is derived based on the voltage ratio of the pair of toroidal coils 10 and 11 and the frequency characteristic of the phase difference. It is difficult to be influenced by the electric field and the change in the electric charge in the liquid, and stable measurement can be performed. That is, according to the electrical characteristic measuring apparatus 100 according to the embodiment of the present invention, the measurement is performed with higher accuracy than the conventional method of deriving the electrical characteristic of the measurement object using an alternating voltage having a single frequency. It is possible.

  In the above-described embodiment, the case where the electrical property measuring apparatus 100 derives both the conductivity and the relative dielectric constant as the electrical properties of the liquid to be measured has been illustrated, but the configuration is such that one of these is derived. May be.

  In the above embodiment, the case where the electrical characteristics of the liquid to be measured is derived using the frequency characteristics of both the voltage ratio and the phase difference of the input / output voltages of the pair of toroidal coils 10 and 11 is exemplified. The electrical characteristics may be derived using the frequency characteristics of either the ratio or the phase difference. However, it is considered that more accurate measurement values can be obtained by using the frequency characteristics of both the voltage ratio and the phase difference.

In the above embodiment, the voltage ratio (or phase difference) acquired for the liquid to be measured is extracted when extracting the reference frequency characteristic approximate to the frequency characteristic of the voltage ratio (or phase difference) acquired for the liquid to be measured. ) And the absolute value of the difference value of the voltage ratio (or phase difference) in the reference frequency characteristic for each frequency, and the total value S _i obtained by adding the absolute values of the difference values calculated for each frequency is an index value However, the present invention is not limited to this, and other index values indicating the degree of approximation between the frequency characteristic of the voltage ratio (or phase difference) acquired for the liquid to be measured and the reference frequency characteristic are used. It is good as well.

  Further, in the above embodiment, the case where the frequency of the AC voltage is changed by 100 kHz in the range of 100 kHz to 1 MHz and the voltage ratio and the phase difference are obtained for each frequency is exemplified. The number of frequencies can be changed as appropriate. For example, only two AC voltages having different frequencies may be supplied to the toroidal coil 10 to obtain a voltage ratio and a phase difference for each frequency. By reducing the number of frequencies supplied to the toroidal coil 10, it is possible to increase the processing speed. On the other hand, the measurement accuracy can be improved by expanding the frequency range and increasing the number of frequencies.

  In the above-described embodiment, the case where the shape of the container 20 is a rectangular ring is illustrated. However, the present invention is not limited to this, and may be an annular ring, for example. Moreover, the cross-sectional shape of the pipe line of the container 20 and the dimensions of each part can be appropriately changed according to the size of the toroidal coils 10 and 11 and the like.

  In the above embodiment, the case where the turns ratio of the input-side toroidal coil 10 and the output-side toroidal coil 11 is 1: 1 is exemplified, but the present invention is not limited to this. For example, the number of turns of the output side toroidal coil 11 may be larger than the number of turns of the input side toroidal coil 10.

  Moreover, although said embodiment illustrated the case where the voltage ratio measurement part 32 and the phase difference measurement part 34 were comprised with an oscilloscope, it is not limited to this. For example, by measuring the input voltage input to the toroidal coil 10 and the output voltage output from the toroidal coil 11 at a predetermined sampling period, and processing the measurement value output from the voltage measuring instrument. And an arithmetic processing device for deriving a voltage ratio and a phase difference.

[Second Embodiment]
FIG. 30 is a functional block diagram showing the configuration of the electrical characteristic measuring apparatus 101 according to the second embodiment of the present invention. In FIG. 30, the same components as those in the electrical characteristic measuring apparatus 100 according to the first embodiment are given the same reference numerals. The electrical property measuring apparatus 101 according to the second embodiment includes a determination unit 51 instead of the electrical property deriving unit 50 of the electrical property measuring apparatus 100 according to the first embodiment.

The determination unit 51 compares the obtained frequency characteristics of the voltage ratio and phase difference for the liquid to be measured with the reference frequency characteristics stored in advance in the storage unit 40. The determination unit 51 outputs a predetermined determination result when the frequency characteristic acquired for the liquid to be measured and the frequency characteristic of the phase difference and the index value indicating the degree of approximation of the reference frequency characteristic are equal to or greater than a predetermined value. As an index value indicating the degree of approximation, as in the first embodiment, the absolute value of the difference between the voltage ratio (or phase difference) acquired for the liquid to be measured and the voltage ratio (or phase difference) in the reference frequency characteristic is used. It is possible to calculate a value for each frequency and use a total value S _i obtained by adding the values.

  The determination unit 51 determines a predetermined determination result when the index value indicating the degree of approximation between the frequency characteristic of one of the voltage ratio and the phase difference acquired for the liquid to be measured and the reference frequency characteristic is equal to or greater than a predetermined value. May be output. Further, in the electrical characteristic measuring apparatus 101 according to the present embodiment, the storage unit 40 only needs to store at least one reference frequency characteristic as a determination reference that is used for the determination process by the determination unit 51. . In the present embodiment, the reference frequency characteristic is a target determination for the liquid to be measured in addition to the resistance element having a known resistance value and the capacitance element having a known capacitance value as described above. It is possible to set an arbitrary frequency characteristic as the reference frequency characteristic so that it can be performed.

  As described above, the electrical property measuring apparatus 101 according to the second embodiment does not derive a measured value of electrical properties such as the electrical conductivity and relative permittivity of the liquid to be measured. The determination result of whether or not it has the characteristic is derived. For example, as described above, the electrical characteristic measurement apparatus 101 according to the second embodiment may derive a determination result as to whether dialysis is completed in artificial dialysis or the like. In this case, the frequency characteristic of the blood voltage ratio or phase difference when dialysis is completed is stored in the storage unit 40 as the reference frequency characteristic. Moreover, as described above, the electrical characteristic measurement apparatus 101 according to the second embodiment may derive a determination result regarding the taste of food.

10, 11 Toroidal coil 20 Container 30 Signal oscillator 32 Voltage ratio measurement unit 34 Phase difference measurement unit 40 Storage unit 50 Electrical characteristic deriving unit 51 Determination unit 60 Control unit

Claims (11)

A container for accommodating the measurement object such that the measurement object forms an annular current path;
A first toroidal coil and a second toroidal coil arranged to be electromagnetically coupled to a current flowing through the annular current path;
Voltage input means for sequentially inputting a plurality of alternating voltages having different frequencies to the first toroidal coil ;
An input voltage to be input before Symbol first toroidal coil, and an output voltage outputted from said second toroidal coil, acquisition means for acquiring at least one frequency characteristic of the voltage ratio and phase difference,
Derivation means for deriving electrical characteristics of the measurement object based on frequency characteristics of at least one of the voltage ratio and the phase difference acquired by the acquisition means;
Electrical characteristic measuring device including A frequency characteristic of at least one of a voltage ratio and a phase difference between the input voltage and the output voltage when the electrical conductivity and relative dielectric constant in the container are known is set as the reference frequency characteristic to the electrical conductivity and relative dielectric constant. A storage unit that stores the plurality of reference frequency characteristics corresponding to each of the plurality of electrical conductivity and relative dielectric constant;
The derivation means extracts a reference frequency characteristic that most closely approximates at least one of the voltage ratio and the phase difference acquired by the acquisition means from among the plurality of reference frequency characteristics stored in the storage unit. The electrical characteristic measuring device according to claim 1, wherein at least one of conductivity and relative permittivity corresponding to the extracted reference frequency characteristic is derived as an electrical characteristic of the measurement object.   The derivation unit is configured to determine a conductivity and a relative dielectric constant corresponding to a reference frequency characteristic that is most approximate to a frequency characteristic of the voltage ratio acquired by the acquisition unit, and a frequency characteristic of the phase difference acquired by the acquisition unit. The electrical property measuring apparatus according to claim 2, wherein the electrical conductivity and relative dielectric constant of the measurement object are derived based on both the electrical conductivity and relative dielectric constant corresponding to the closest reference frequency characteristic. A container for accommodating the measurement object such that the measurement object forms an annular current path;
A first toroidal coil and a second toroidal coil arranged to be electromagnetically coupled to a current flowing through the annular current path;
Voltage input means for sequentially inputting a plurality of alternating voltages having different frequencies to the first toroidal coil ;
An input voltage to be input before Symbol first toroidal coil, and an output voltage outputted from said second toroidal coil, acquisition means for acquiring at least one frequency characteristic of the voltage ratio and phase difference,
Derivation means for deriving a determination result relating to the specification or property of the measurement object based on the frequency characteristic of the voltage ratio and the phase difference acquired by the acquisition means;
Electrical characteristic measuring device including A storage unit that stores a reference frequency characteristic used as a determination criterion when the deriving unit derives a determination result related to the measurement object;
The deriving unit determines the measurement object based on a comparison result between at least one frequency characteristic of the voltage ratio and the phase difference acquired by the acquiring unit and a reference frequency characteristic stored in the storage unit. The electrical property measuring device according to claim 4 which derives a result.   The container includes an inlet-side channel into which the measurement object flows and an outlet-side channel from which the measurement object flows out, and a wall separating the inlet-side channel and the outlet-side channel is half The electrical property measuring device according to claim 1, comprising a permeable membrane.   The said container contains the pipe line through which the said measurement object distribute | circulates, and the conductor wiring electrically connected with the measurement object through which the both ends distribute | circulate the inside of the said pipe line. The electrical property measuring apparatus described in 1.   The electrical characteristic measuring device according to claim 1, wherein the frequency of the AC voltage includes a range from 100 kHz to 1 MHz. Accommodating the measurement object in a container such that the measurement object forms an annular current path;
Arranging a first toroidal coil and a second toroidal coil so as to be electromagnetically coupled to a current flowing through the annular current path;
Sequentially inputting a plurality of alternating voltages having different frequencies to the first toroidal coil ;
An input voltage to be input before Symbol first toroidal coil, and an output voltage outputted from said second toroidal coil, and obtaining at least one frequency characteristic of the voltage ratio and phase difference,
Deriving electrical characteristics of the measurement object based on frequency characteristics of at least one of the voltage ratio and the phase difference;
A method for measuring electrical characteristics including: Accommodating the measurement object in a container such that the measurement object forms an annular current path;
Arranging a first toroidal coil and a second toroidal coil so as to be electromagnetically coupled to a current flowing through the annular current path;
Sequentially inputting a plurality of alternating voltages having different frequencies to the first toroidal coil ;
An input voltage to be input before Symbol first toroidal coil, steps and the voltage ratio for obtaining at least one frequency characteristic of the voltage ratio and phase difference between the output voltage outputted from said second toroidal coil, and Deriving a determination result relating to the measurement object based on at least one frequency characteristic of the phase difference; and
A method for measuring electrical characteristics including:   The program for functioning a computer as the said derivation | leading-out means in the electrical property measuring apparatus of any one of Claims 1 thru | or 8.